The Research Of Output Series Hybrid Linear-pwm Power Converter

Power converter is used to transfer one kind of energy form into another one or more. In recent years, because of the high efficiency and fast response, PWM power converters gradually replaced the linear power converters. However, the PWM power converters have harmonic problem that affects the positioning accuracy and stability of the motor. But linear power converters have high positioning accuracy, which makes linear power converters still exist. Thus, the two kinds of power converters are combined to obtain the advantages of both structures. The research of the output series hybrid linear-PWM power converter is a combination of linear power converter and PWM power converter, which has advantages such as high precision, high response and high efficiency.First of all, the structure of power converter is given, and the feature of the converter is analyzed. Meanwhile, the theory of the given structure is analyzed, and then the loss calculation method in two modes is given.The output series hybrid linear-PWM power converter works in SVPWM mode. In this paper, the principle of SVPWM modulation for power converter and how to divide the sectors and the regions and the characteristics of switching of the power converter is analyzed, and then switch states is summarized. Finally, the method of the calculation of the switching time and the pulse generator method are given and simulated.When the output series hybrid linear-PWM power converter works in the linear mode, the sinusoidal signal is amplified by the amplification and then transferred to the power converter to control the motor. By analyzing the reason of the distortion of the linear power converter, the design method of the power converter is improved, which eliminates the crossover distortion. The linear power converter is also analyzed by simulation.The hardware for power converter is designed including the protection circuit of over-current, over-voltage and under-voltage and the PWM drive circuit and the linear drive circuit. The software of the power converter is designed and tested finally.